FIG. 1 shows high-level architecture which can help to improve a bandwidth of a data connection between a client end user and the Internet. The solution shown in FIG. 1 uses two connections from a client 30 to an internet server 20 accessible over the Internet, e.g. a fixed network 11, such as a DSL connection, and a mobile network 12. This solution is known as multipath TCP based hybrid access solution for hybrid access which is based on multipath TCP (transfer control protocol) as defined in IETF.
The solution involves a customer premises equipment, CPE, 10 on the client side, which provides at least two interfaces, e.g. two WAN (wide area network) interfaces, such as DSL and LTE communicating with a proxy, such as multi-service proxy, MP-TCP Proxy 17 of FIG. 1. For the download of data from the internet server 20 the data can be split at MP-TCP Proxy17 and sent via the fixed network 11 and BNG (border network gateway) 14 to CPE 10 and via the mobile network 12 passing PGW 13 (packet gateway). A policy control entity 16 controls the policies required for the data transmission. Between the CPE device and the client end device and between MSP 17 and the Internet servers, normal TCP is used.
A remote access by a client to home content, e.g. as stored on a home server connected to a home client 30 and/or CPE 10, is one important use case. Since DSL speeds are highly asymmetric, remote access to home content suffers from uplink limitations. By way of example, in case of a 6 Mbps (Mega bit per second) DSL line, only 600 kbps (kilo bit per second) are typically available in the uplink direction. For a remote user requesting data from a residential server, these uplink limitations will become a bottleneck for transmitting data from the residential server to the remote user. Thus, it would be desirable to benefit from the hybrid access shown in FIG. 1 so that data from the client 30 can be sent to a remote client using two transmission networks.
However, the remote access cannot be supported in a straightforward way by the architecture as shown in FIG. 1. This non-existing support is based on the following two problems:                First of all, currently there exists no possibility that the network initiates a wireless IP connection over a mobile communications network such as 2G/3G or 4G. For security reasons, any IP connection can only be triggered by an end device holding a SIM (Subscriber Identity Module) card. Thus, a cellular data connection over a cellular network cannot be established from a network proxy.        Secondly, it cannot be assumed that the remote client in the public Internet knows the address of the network proxy. It only knows the fully qualified domain name (FQDN) of the home server. A CPE 10 gets public IP addresses assigned which can change dynamically. Today, a remote access to a CPE 10 always requires the use of the FQDN. The CPE is configured for updating the mapping between this FQDN and a public IP address whenever the public IP address changes. In this way, it can be guaranteed that whenever a user uses the FQDN, it is routed to the CPE device at home.        
Thus, one problem in a hybrid access scenario for remote access it that the connection establishment is always made via TCP as it is initiated by a non-MP(multipath)-TCP capable end device. Since normal IP routing is used, this TCP session is terminated at the CPE devices. Thus, it is currently not possible to involve the MP-TCP proxy 17.